Device for the feed of grinding tools to grinding machines

ABSTRACT

A feed device for grinding machines, for example, circular and thread grinding machines, in which the grinding tool and the work-piece are slidable relatively to one another, and in which a trimming device provided with one or more trimming tools is mounted on a slidable adjusting or trimming carriage which before the commencement of a trimming operation is fed a predetermined amount closer to the grinding tool, whereby in order to compensate for the decrease in size of the grinding disk resulting from the adjustment, a change in position of the grinding tool takes place with reference to the work-piece.

llnited States Patent Wirz 1 Dec. 30, 1975 [5 1 DEVICE FOR THE FEED 0F GRINDING 3,033,187 5/1962 Wespi 125 11 cw TOOLS 0 GRINDING MACHINES 3,640,024 2/1972 Stahn 51/5 D 3,815,568 6/1974 Gerner 125/11 CW X [75] Inventor: Walter Wn'z, D1etl1kon, Switzerland [73] Assignee: Reishauer AG., Switzerland Primary Examiner-D0nald G. Kelly Attorney, Agent, or Firm-Hill, Gross, Simpson, Van 22 F l d. l l l 6 Sept 1974 Santen, Steadman, ChIara & S1mpson [21] Appl. No.: 505,059

30 F [57] ABSTRACT orei n A lication Priorit D t l S t 17 i d y a a A feed device for grinding machines, for example, circp wltzer an 13303/73 cular and thread grinding machines, in which the grinding tool and the work-piece are slidable relatively 51/5 to one another and in which a trimming device 58 F .ld 125 11 vided with one or more trimming tools is mounted on I 1 0 can l a slidable adjusting or trimming carriage which before I the commencement of a trimming operation is fed a predetermined amount closer to the grinding tool, [56] References cued whereby in order to compensate for the decrease in UNITED STATES PATENTS size of the grinding disk resulting from the adjustment, 1,573,153 2/1926 Garrison 125/11 B a change in position of the grinding tool takes place 2,720,063 10/1955 Hill 125/11 CW with reference to the work-piece. 2,929,172 3/1960 Pasell 125/11 CW X 2,946,162 7/1960 Mader 125/11 CW X 9 Claims, 11 Drawing Figures US. Patent Dec.30, 1975 Sheet 10f4 3,928,943

US. Patent Dec. 30, 1975 Sheet 2 of4 Sheet 3 0f 4 US. Patent Dec. 30, 1975 m. L. 3 E e ss J U.S. Patant Dec. 30, 1975 -Fig.8 45

Sheet 4 of 4 DEVICE FOR THE FEED OF GRINDING TOOLS TO GRINDING MACHINES This invention relates to grinding machines such as the circular or thread-grinding type and, more particularly, to a trimming tool feed device for use in conjunction therewith.

In known devices, the amount of change in the position of the grinding tool with reference to the workpiece, to compensate for the decrease in size of the grinding disk taking place during the trimming corre sponds exactly with the amount of feed of the adjusting or trimming tool.

Since during trimming the trimming tool is subjected to a wear, that is, a constant change in size and the rigidity of the grinding tool as the diameter decreases and also the rigidity of the grinding and the adjustingcarriagc, changes on account of the different position in the associated guideways, the amount by which the trimming tool is fed against the grinding tool does not correspond with the effective diminution of the diameter of the grinding tool caused by the trimming operation. The feed of the grinding tool in respect of the work-piece corresponding to the amount of feed of the trimming tool accordingly results in work-pieces not exactly accurate as to size.

Accordingly, it becomes appropriate to provide means by which this disadvantage may be overcome.

It is an object of this invention to provide means whereby the unavoidable wear of the trimming tool and the changes in rigidity of the different elements influencing the actual amount of adjusting during the feed of the grinding tool (or the trimming tool) may be taken into consideration in order to compensate for the decrease in size of the grinding disk resulting during the trimming by amounts determined from experience.

It is a further object to achieve the above by providing control means which enforce upon a threaded spindle which effects the shifting of the trimming carriage an additional displacement which takes into consideration the wear of the trimming tool, the rigidity of the grinding disk which changes with decreasing diameter, and the changing rigidity of guides for the grinding and trimming devices.

Other objects and advantages of the invention will become more apparent when the following description is considered in conjunction with the following drawmgs.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows a front view in elevation of a thread grinding machine;

FIG. 2 shows a longitudinal section taken through the grinding carriage along line IIII of FIG. 3;

FIG. 3 shows a vertical section taken through the adjusting or trimming carriage along line IIIIII of FIG. 2;

FIG. 4 shows a section transversely through the support or through the slide device arranged in it along IV-IV of FIG. 2;

FIGS. 5 to 8 are illustrations of the slide devices with FIG. 7 is a top view of the slide device in which the template has a straight profile and the groove a cam profile;

FIG. 8 is a top view of the :slide device in which the templates and the grooves have a straight profile;

FIGS. 9 and 10. are diagrammatic showings of the sliding movements of support and trimming carriages; and

FIG. 11 is a diagrammatic showing as to the production of the additional sliding.

DESCRIPTION OF PREFERRED EMBODIMENTS The thread grinding machine shown in FIG. 1 has a frame or bed 1 which serves as base for the slidable reception of the work-piece carriage 2 and the grinding carriage 3.

- On the work-piece carriage 2 is fastened the workpiece headstock 4, in which the workpiece spindle 5 is rotatably positioned. On the table surface F of the work-piece carriage 2 is arranged the tailstock 6 so as to be slidable longitudinally. The work-piece 7 is clamped in the normal manner between the centering tips 8 and 9 and is set into rotation by the actuator disk 10 which is connected with the work-piece spindle 5 through a lathe dog 11 or another actuator means. The drive of the work-piece spindle S and the slide device of the work-piece carriage 2 as well as other elements of the machine tool having no influence on the device of the invention are not specifically shown or mentioned as they are generally known in machine tools of the type under consideration.

The grinding carriage 3 is slidably arranged in a guideway G on the frame 1 transversely to the axis of the work-piece H. The sliding or shifting of the grinding carriage 3 shown in FIGS. 2 and 3 is accomplished by rotation of the hand-wheel 13 with the aid of a rotatable thread spindle 12 axially positioned in the grinding carriage 3 and secured in. the spindle nut thread I on the frame 1.

On the grinding carriage 3 :is arranged a swingable rocker 14 (FIGS. 2, 3) on which is disposed the support 15 slidable transversely to the axis H of the work-piece. On the support 15 is fixed the grinding motor 16 which, through the grinding spindle 17 (FIG. 3), drives the grinding wheel 21 rotatably positioned in the support 15.

Furthermore, the support 15 carries the trimming carriage 18 slidably arranged transversely to the grind.- ing wheel axis K, to which is clamped a trimming device 19corresponding to the particular purpose, with one or more trimming tools 20 (FIG. 2). Due to the swingable rocker 14, the grinding wheel 21 as well as the support 15 with the grinding wheel 21, the grinding motor 16, the grinding spindle .17, the trimming carriage 18 and the trimming device 19 may be disposed at a predetermined angle 7 (FIG. 1) with respect to the work-piece axis H. With the aid of the clamping screw 22 the rocker 14 is fixed in the desired position.

On, the trimming carriage 1.8 may be clamped, as already mentioned, any desired trimming device 19 depending on the desired purpose.

For clamping the trimming device 19 (FIG. 2) in the proper position, there are provided-on the adjusting carriage 18, a wedge shaped stop-strip 37 and a straight stop-strip 38 which are fastened withscrews 3) on the adjusting carriage 18. The trimming device 19 is tightly held in ,place with a clamping chucking wedge 41 secured to the carriage 18 with screws 40. The trimming device 19 shown in FIG. 2 is used toadjust or trim a grinding disk 21 which is intended for the grinding of trapezoidal-threads (FIG. 3). The trimming tool 20 is arranged in a carriage'42 which is'slidingly disposed parallel to the grinding wheel axis K and is slidingly moved by means of the thread spindle 43 rotatable by a hand wheel 44. i

The support 15 is slidingly disposed in the groove L of the rocker 14 transversely to the axis H of the workpiece. A shifting of the support 15 which only serves for the adjusting compensation of the grinding disk 21, however, takes place solely in connection with a simultaneous shifting of the trimming carriage 18 in the same direction. Thelatter is slidably arranged in a groove M on the support 15 to move transversely to the grinding disk axis K. The simultaneous shifting of the support 15 and the adjusting carriage 18 takes place by means of rotation of the hand-wheel 23 with which the thread spindle 24 is connected'and which has a left-hand pitch and is secured in the spindle nut thread N of the trimming carriage 18. The threaded spindle 24 is held in an axial bearing 25 (FIGS. 2, 4) which is longitudinally slidable in the support 15 for the purpose of carrying out the later corrective shifting C of the trimming carriage 18 still to be hereinafter described. At the end of the mentioned threaded spindle 24 is fixed a gear wheel 26 which engages with a mating gear formed on axially extending spindle nut 27 which is rotatable in the support 15 but is held against longitudinal movement. The spindle nut 27 likewise possesses a left-hand thread exactly corresponding to the thread 24 and is in engagement with the threaded spindle 28 which is held against axial movement in the rocker '14 by means of the screw 29. The threaded spindle 28 is furthermore secured against rotation in the support 15 in a square groove 0.

Upon rotation of the hand-wheel 23 and the threaded spindle 24 with left-handed pitch in-clockwise direction (FIGS. 2 and 9), the trimming carriage 18 and with it the trimming tool 20 is fed on the support 15 for a given amount B (FIG. 9) against the grinding wheel 21 positioned on the support 15. At the same time, however, the support 15 with the grinding disk 21 and the adjusting carriage 18 is also moved by means of the spindle nut 27 with left-handed pitch likewise'set in rotation by the hand-wheel 23 (FIG. 2) by a similar amount A toward the work-piece 7. The mentioned amount of feed B of the adjusting carriage 18 caused by the rotational movement of the associated threaded spindle 24 corresponds exactly with the amount of feed A of the support 15 or the grinding disk 21 respectively, agains't the work-piece 7.

Under these conditions the following situation re-. sults: The wear of the trimming tool-20 and the changeable rigidities of the parts mentioned above result'in'the layer T actually removed by trimming the grinding disk 21 being smaller than the amount of feed B on the adjusting tool 20 (FIG. 9). The diameter D of the trimmed grinding disk 21 is accordingly greater by an amount 2C than the desired diameter D1. The amount 2C corresponds to the wear of the trimming tool 21) and that part of the elastic deformation dependent upon the rigidities of the parts mentioned above. The work-piece 7 has after grinding a diameter d1 (FIG. 9) which is smaller than the required diameter d by the amount of 1 riage would have to be increasedby the amount C, that is, by the so-callcd correctionalshifting. In other words",

(see FIG. so that on the grinding disk 21- a layer'of the depth Tl will be removed which corresponds to the I amount of feed A of the grinding disk 21, that is The new device for carrying out the correctional shifting of the trimming carriage 18 (.FIGS. 2, 4, 5, 6, 7 and 8) consists .of an exchangeable slide member 30 which is for slidable movement in the support transversely to the guide L which guides the movement of support 15. The slide member 30 has a groove P whose shape may be-empirically determined. A slide bolt 31 attached to longitudinally slidable .axial bearing slides freely in groove-P free from play; A positive or negative longitudinal shifting movement of the axial bearing 25, of the threaded spindle 24, of the trimming carriage 18 and the trimming device 19 itself, with reference to the support 15 or with reference to the grinding-disk 21 associated with the latter is correlated with each shifting movement of the slide member following the path'of the groove P and the direction of movement of the slide member 30. If the groove P is a straight slot, (FIGS. 6"and 8) is only inclined to the sliding direction of the slide member 30, a square key Q (FIGS. 2, 6 and 8) may be arranged on the axial bearing 25 instead of the 'slide'bolt 31.

A transverse sliding of the slide member 30 is controlled by a template 32 which is fixed on the adjusting carriage 18 (FIGS. 4, 6, and 8), and on which slides the guide pin 33 connected to the slide member 30.

The template 32,"when its control edge R extends in a straight line (FIGS. 7, 8) may also be formed as an adjustable arm 34 which is swung about a rotary pin 35 in the desired angle of inclination B and then may be secured in this position by means of a clamping screw 36. The compression springs inserted between the slide member 30 and the support 15 insure an installation wherein the measuring pin 33 is free from play on the'template 32 or on theadjustable arm 34, respectively,

Depending on the requirements, the groove P and the template 32 may in each case both have a cam-shaped profile (FIG.,5) or the groove Pia straight and the template 32 a cam-shaped profile (FIG. 6), or vice versa, the groove P may have a cam-shaped and the template 32 or the arm 34 a straight profile (FIG. 7) or also the groove P and the template 32 or the arm 34 mayboth have astraight profile (FIG. 8

Upon a rotation of the hand-wheel 23 by an amount which causes a shifting by an amount A on the support 15, a shifting E= 'B'+ C (FIG. 10) may be completed on the adjusting carriage 1 8, The template 32 arranged on the adjusting carriage 18 or the adjustable arm 34 fixed to it take part in this shifting. By means of the guide pin 33 which continuously abuts onthe control edge R of the template 32 or thearm '34,.the slide member 30 is pushed by the amount U (FIG. 11) in the support 15 transverselyto its guidemember L (FIGS. 2, 5, 6, 7 and 8). When the slide member 30 is. shifted'an amount U, there is imparted to the adjusting carriage- 18 an additional shifting of the desired amount C through the axial bearing 25 with its associated guide pin 31 moving in groove P. The same general action takes place whether the groove P is cam-shaped or a straight slot.

The changes of position of the device of the invention which changes are associated with the shifting movements A or B C E, respectively, are diagramatically illustrated in FIG. 11, from which it is seen how the additional shifting movement C occurs.

In the described embodiment the slide member 30 is positioned in the support while the template 32, 34 is located on the adjusting carriage 18. Obviously the arrangement could be reversed.

What is claimed is:

l. A feed device for grinding machines having a support with which a grinding wheel is operatively associated and on which it is supported and in which the support and rotatable work-piece are slidable relative to each other comprising:

a slidable adjusting carriage;

a trimming device mounted on said carriage, said trimming device being adapted to have a trimming tool disposed therein;

means for shifting said adjusting carriage transversely to the grinding wheel axis, said shifting means including a threaded spindle slidably disposed in the support and in threaded engagement with said adjusting carriage;

control means interconnecting the support and said adjusting carriage to provide an additional shifting of the adjusting carriage;

said control means including a slide member which is carried by the support and which is shifted during the adjustment operation transversely to the grinding carriage guide, said slide member having a groove or slot formed therein; and

a slide pin which is guided in said groove or slot to thereby impart additional shifting to the threaded spindle.

2. The device of claim 1 wherein said groove or slot has a profile the shape of which is empirically determined.

3. The device of claim 1 including a template fixed on said adjusting carriage; and

a guide pin fixed on said slide member and in contact with said template to control the movement of the adjusting carriage.

4. The device of claim 1 wherein said slide member is slidably disposed on the support.

5. The device of claim 4 including a template fixed on said adjusting carriage; and

a guide pin fixed on said slide member and in contact with said template to control the movement of the adjusting carriage.

6. The device of claim 1 wherein said slide pin is connected to a longitudinally slidable axial bearing on the threaded spindle for bringing about additional shifting of said threaded spindle and said trimming device.

7. The device of claim 1 wherein said slide member is positioned in the support; and

said slide pin is connected to an axial bearing on the threaded spindle for bringing about additional shifting of said threaded spindle and said trimming device. A

8. The device of claim 7 including a template fixed on said adjusting carriage; and

a guide pin fixed on said slide member and in contact with said template to control the movement of the adjusting carriage.

9. The device of claim 6 wherein said template is adjustable so that its control edge may be positioned at a plurality of angles. 

1. A feed device for grinding machines having a support with which a grinding wheel is operatively associated and on which it is supported and in which the support and rotatable work-piece are slidable relative to each other comprising: a slidable adjusting carriage; a trimming device mounted on said carriage, said trimming device being adapted to have a trimming tool disposed therein; means for shifting said adjusting carriage transversely to the grinding wheel axis, said shifting means including a threaded spindle slidably disposed in the support and in threaded engagement with said adjusting carriage; control means interconnecting the support and said adjusting carriage to provide an additional shifting of the adjusting carriage; said control means including a slide member which is carried by the support and which is shifted during the adjustment operation transversely to the grinding carriage guide, said slide member having a groove or slot formed therein; and a slide pin which is guided in said groove or slot to thereby impart additional shifting to the threaded spindle.
 2. The device of claim 1 wherein said groove or slot has a profile the shape of which is empirically determined.
 3. The device of claim 1 including a template fixed on said adjusting carriage; and a guide pin fixed on said slide member and in contact with said template to control the movement of the adjusting carriage.
 4. The device of claim 1 wherein said slide member is slidably disposed on the support.
 5. The device of claim 4 including a template fixed on said adjusting carriage; and a guide pin fixed on said slide member and in contact with said template to control the movement of the adjusting carriage.
 6. The device of claim 1 wherein said slide pin is connected to a longitudinally slidable axial bearing on the threaded spindle for bringing about additional shifting of said threaded spindle and said trimming device.
 7. The device of claim 1 wherein said slide member is positioned in the support; and said slide pin is connected to an axial bearing on the threaded spindle for bringing about additional shifting of said threaded spindle and said trimming device.
 8. The device of claim 7 including a template fixed on said adjusting carriage; and a guide pin fixed on said slide member and in contact with said template to control the movement of the adjusting carriage.
 9. The device of claim 6 wherein said template is adjustable so that its control edge may be positioned at a plurality of angles. 